This self-healing concrete takes the cracks out of houses.
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Most modern buildings are made of reinforced concrete, which has a typical lifespan of 50 years and is subject to cracks over time. It costs a lot of money to repair these cracks. According to incomplete statistics, in the European Union alone, the maintenance of bridges and tunnels costs 6 billion euros per year. And all this is about to change, Hendrik Jonkers, a microbiologist and inventor from the Netherlands, who invented a concrete that can repair itself – Bio-concerte.
Inspired by the human body’s formation of bone cells through calcification, Jonkers tried to find a bacterium that could live in an alkaline environment and make its own limestone, and after more than three years of dedicated research, he finally found the bacillus bacterium. The bacillus bacteria can survive in limestone and produce spores, but it needs to add sugar to provide it with nutrients, mix it into concrete, apply it to the cracks, and when there is water penetrating into it, the bacteria will produce limestone and the cracks will be repaired intact automatically. Repairing cracks in this way is usually good in about 3 weeks. In addition, this bacteria can survive in concrete for 200 years. This also means that buildings with it will not have cracks after two centuries, greatly extending the life of the building. It is also a good solution to the current problem of restoring old buildings. Based on this technology, Professor Jonkers has developed three products, self-healing concrete, repair cement mortar and repair solution, which have been applied to an old building in the Netherlands.
Two liquids were sprayed on the cracked wall, the first containing limestone with bacteria and PH buffer and the second containing organic calcium compounds and inorganic nutrients. The two liquids penetrated the cracks and the bacteria produced large amounts of calcium carbonate to fill the cracks, thus fixing them. This material gives life to the building, just like a tree, even if the branches and leaves are broken, it doesn’t matter, they will grow back, and most importantly, if you build a house with it, no cracks are expected for 200 years.